Compounds, compositions and process

Abstract

Described are compounds characterized by the following formula: ##STR1## wherein C n H 2n is alkylene from 2 to 12 carbon atoms and C m H 2m is alkylene from 2 to 20 carbon atoms. Each of the alkylene groups can, optionally, be substituted by inert substituents. The compounds contain a free isocyanato group and a masked isocyanate group, namely, the cyclic urea moiety, which, when the compounds are heated, preferably in the presence of a catalyst, opens to give the group OCN--C n H 2n --. Thus, the compounds can be reacted via the free isocyanate group with active hydrogen-containing monomers or polymers to form storage stable compositions which, upon heating, are curable via reaction with the cyclic urea group.

We claim: 
     
       1. A compound having the formula ##STR6## wherein C n  H 2n  represents alkylene from 2 to 12 carbon atoms, inclusive, and C m  H 2m  represents alkylene from 2 to 20 carbon atoms, inclusive, and C n  H 2n  and C m  H 2m  are each independently substituted by from 0 to 2n inert substituents and 0 to 2m substituents, respectively. 
     
     
       2. A compound according to claim 1 wherein C n  H 2n  represents 1,3-propylene and C m  H 2m  represents ethylene, said compound being N-(3-isocyanatopropanoyl)hexahydropyrimidin-2-one. 
     
     
       3. A compound according to claim 1 wherein C n  H 2n  represents 1,3-propylene and C m  H 2m  represents 1,5-pentylene, said compound being N-(6-isocyanatohexanoyl)hexahydropyrimidin-2-one. 
     
     
       4. An adduct obtained by reacting a compound according to claim 1 with a low molecular weight polyfunctional active hydrogen containing compound in proportions such that the ratio of total free isocyanate groups to total active hydrogen containing groups is substantially 1.0. 
     
     
       5. An adduct according to claim 4 obtained by reacting substantially 3 molar proportions of N-(3-isocyanatopropanoyl)hexahydropyrimidin-2 one with substantially 1 molar proportion of trimethylolpropane, said adduct corresponding to the formula: ##STR7## 
     
     
       6. An adduct according to claim 4 obtained by reacting substantially 3 molar proportions of N-(6-isocyanatohexanoyl)hexahydropyrimidin-2-one with substantially 1 molar proportion of trimethylolpropane said adduct corresponding to the formula: ##STR8## 
     
     
       7. An adduct according to claim 4 obtained by reacting substantially 3 molar proportions of N-(6-isocyanatohexanoyl)hexahydropyrimidin-2-one with substantially 1 molar proportion of trimethylolethane said adduct corresponding to the formula ##STR9## 
     
     
       8. A process for the preparation of a polyurethane which comprises reacting a compound according to claim 1 with a polyol in the presence of a urethane catalyst and heating the reaction mixture at a temperature sufficient to effect ring opening of the hexahydropyrimidin-2-one moiety. 
     
     
       9. A process for coating a substrate with a polyurethane coating, said process comprising reacting a compound according to claim 1 with a polyol in the presence of a urethane catalyst at a temperature sufficient to allow reaction between the free isocyanate group in said compound of claim 1 and hydroxyl groups in said polyol but insufficient to cause ring opening of the hexahydropyrimidin-2-one moiety, applying the product so obtained as a coating to a substrate and subsequently curing said coating by heating to a temperature at which ring opening of said hexahydropyrimidin-2-one moiety occurs. 
     
     
       10. A process according to claim 9 wherein the compound according to claim 1 employed therein is N-(3-isocyanatopropanoyl)hexahydropyrimidin-2-one. 
     
     
       11. A process according to claim 9 wherein the compound according to claim 1 employed therein is N-(6-isocyanatohexanoyl)hexahydropyrimidin-2-one. 
     
     
       12. A process according to claim 9 wherein the reaction is carried out in the presence of an inert solvent. 
     
     
       13. A process according to claim 9 wherein the reaction is carried out in the absence of an inert solvent. 
     
     
       14. A process for applying a coating of polymer containing active hydrogen groups to a substrate which comprises the steps of: admixing an adduct according to claim 4 with said polymer and a urethane catalyst at a temperature less than that required to effect ring opening of the hexahydropyrimidin-2-one moiety in said adduct to claim 4;   applying the resulting product as a coating to said substrate; and   heating said coating to a temperature sufficient to effect ring opening of said hexahydropyrimidin-2-one moiety.   
     
     
       15. A process according to claim 14 wherein said adduct is that obtained by reacting substantially 3 molar proportions of N-(3-isocyanatopropanoyl)hexahydropyrimidin-2-one with substantially 1 molar proportion of trimethylolpropane. 
     
     
       16. A process according to claim 14 wherein said adduct is that obtained by reacting substantially 3 molar proportions of N-(6-isocyanatohexanoyl)hexahydropyrimidin-2-one with substantially 1 molar proportion of trimethylolpropane. 
     
     
       17. A process according to claim 14 wherein said adduct is that obtained by reacting substantially 3 molar proportions of N-(6-isocyanatohexanoyl)hexahydropyrimidin-2-one with substantially 1 molar proportion of trimethylolethane. 
     
     
       18. A process for curing a polymer containing active hydrogen groups which comprises heating said polymer with a compound according to claim 1 at a temperature sufficient to effect ring opening of the hexahydropyrimidin-2-one moiety present in said compound.